1. Field of the Invention
This invention relates to a coated ubidecarenone-containing liposome comprising the ubidecarenone-containing liposome and a polysaccharide fatty acid ester applied on the membrane of the liposome.
2. Description of the Prior Art
Ubidecarenone, also known as coenzyme Q.sub.10, has recently come into widespread clinical use as a medicine effective for improving the function of the heart.
There is still room for improvement in the speed of transfer of this substance from the blood to a target organ in intravenous or oral administration. This is the reason why, if this substance is for instance formed into a pharmaceutical preparation in accordance with a conventional technique and administered, the speed of its disappearance from the blood is considerably low, and therefore the speed of its transfer to the target organ and the amount transferred are reduced.
Since ubidecarenone is a normally solid lipid-soluble substance having a melting point of 48.degree. to 52.degree. C., it must be solubilized by a conventional technique involving the use of a surfactant such as HCO (polyoxyethylene-hardened castor oil) in order to render it convenient for intravenous administration. However, if it is administered in the thus solubilized state, the speed of disappearance of ubidecarenone from the blood is low, and the speed of its transfer in the initial stage after administration to the heart, spleen and liver, i.e., the target organs, especially to the heart, is low.